package com.tinet.ccic.wm.commons.util;

import java.net.InetAddress;
/**
 * UUID算法生成器。
 *<p>
 * 文件名： UUIDHexGenerator.java
 *<p>
 * Copyright (c) 2006-2010 T&I Net Communication CO.,LTD.  All rights reserved.
 * @author 周营昭
 * @since 1.0
 * @version 1.0
 */
public class UUIDHexGenerator {

	private String sep = "";
	private static final int IP;
	private static short counter = (short) 0;
	private static final int JVM = (int) (System.currentTimeMillis() >>> 8);

	private static UUIDHexGenerator uuidgen = new UUIDHexGenerator();

	static {
		int ipadd;
		try {
			ipadd = toInt(InetAddress.getLocalHost().getAddress());
		} catch (Exception e) {
			ipadd = 0;
		}
		IP = ipadd;
	}

	public static UUIDHexGenerator getInstance() {
		return uuidgen;
	}

	public static int toInt(byte[] bytes) {
		int result = 0;
		for (int i = 0; i < 4; i++) {
			result = (result << 8) - Byte.MIN_VALUE + (int) bytes[i];
		}
		return result;
	}

	protected String format(int intval) {
		String formatted = Integer.toHexString(intval);
		StringBuffer buf = new StringBuffer("00000000");
		buf.replace(8 - formatted.length(), 8, formatted);
		return buf.toString();
	}

	protected String format(short shortval) {
		String formatted = Integer.toHexString(shortval);
		StringBuffer buf = new StringBuffer("0000");
		buf.replace(4 - formatted.length(), 4, formatted);
		return buf.toString();
	}

	protected int getJVM() {
		return JVM;
	}

	protected synchronized short getCount() {
		if (counter < 0) {
			counter = 0;
		}
		return counter++;
	}

	protected int getIP() {
		return IP;
	}

	protected short getHiTime() {
		return (short) (System.currentTimeMillis() >>> 32);
	}

	protected int getLoTime() {
		return (int) System.currentTimeMillis();
	}

	/**
	 * 生成uuid字符串，长度为32。
	 * @return
	 */
	public String generate() {
		return new StringBuffer(36).append(format(getIP()))
					.append(sep).append(format(getJVM()))
					.append(sep).append(format(getHiTime()))
					.append(sep).append(format(getLoTime()))
					.append(sep).append(format(getCount())).toString();
	}
	
//	public static void main(String[] args) {
//		System.out.println(UUIDHexGenerator.getInstance().generate()); 
//	}
}
